Go is a C++ killer in a different sense: there are things that people would have written in C++ (or often in C) that are today often written in Go instead. Not everything, obviously. But Go is a great Unix glue language for programs too big to write in Shell and often those would be written in C or C++ in the past.
Agree with your statements. Go's history on its Wikipedia page[1] and other sources, explains one of the original points that led to its development was "dislike of C++", where it was causing them all kinds of problems at their office (explained in other sources).
Go was used to replace it, where possible and for their purposes, but not in a 1 to 1 way. That's neither a total replacement for C or C++, but rather a replacement in particular areas they deemed important. Carbon, on the other hand, is going that extra step where the creators of Go didn't want to.
